Answer:
117.83° F
Explanation:
Using Newton's Law of Cooling which can be expressed as:

The differential equation can be computed as:





where;

At the initial condition, T(0)= 350



replacing
= 280 into (1)
Hence, the differential equation becomes:

when;
time (t) = 1 hour
T(1) = 250
Since;



k = -0.4418
Therefore;
T(t) = 70 + 280e^{(-0.4418)}t
After 4 hours, the temperature is:
T(t) = 70 + 280e^{(-0.4418)}4
T(4) = 117.83° F
Answer:
D. The Federal Reserve Bank can provide a short-term loan to banks
to prevent them from running out of money.
Explanation:
A bank run occurs when a large number of depositors withdraw their deposits simultaneously from a bank.
As the number of withdraws increases, the available cash in the bank decreases until a point that the bank can't give depositors their money.
In these situations, The Federal Reserve Bank acts as a lender of last resort that helps to reinforce the effect of deposit insurance, and to reassure bank customers that they will not lose their money.
Answer:
The dolphin's speed is 17 mi/h
Explanation:
Use the formula for average velocity: Distance/time
then the average speed of the dolphin is 51/3 mi/h = 17 mi/h
Answer:
The maximum value of the driving force is 1044.01 N.
Explanation:
Given that,
Weight of the object, W = 50 N
Force constant of the spring, k = 210 N/m
The system is undamped and is subjected to a harmonic driving force of frequency 11.5 Hz.
Amplitude, A = 4 cm
We need to find the maximum value of the driving force. The force is given by the product of mass and maximum acceleration as :
.....(1)
A is amplitude
m is mass,

is angular frequency
Angular frequency is given by :

Equation (1) becomes :

So, the maximum value of the driving force is 1044.01 N.
Answer: All drugs of abuse trigger a surge of dopamine
Explanation: It creates a rush of “wanting” in the brain. This makes us crave more drugs.